| Electric actuators for valves are widely used in petrochemical and other industries.However,traditional electric actuators need to be connected to working parts through a gear transmission system to drive loads.This structure has disadvantages such as low efficiency,high vibration and high failure rate.The direct drive system eliminates the gear transmission system of the intermediate link,which improves the efficiency of the system,the dynamic response speed and the reliability of the system,and reduces the noise and maintenance cost of the system.In addition,the traditional induction motor,switched reluctance motor and permanent magnet synchronous motor used in the direct drive system have the problems of low efficiency,low torque density and poor reliability at low speed,while the new type of transverse flux permanent magnet motor has the characteristics of high efficiency,high power density and high reliability at low speed,which has a good application prospect as the electric actuator of the direct drive system.This paper uses the magnetization effect of the U-shaped magnetization structure to propose a U-shaped Flux-concentrated Transverse Flux Permanent Magnet Motor(FCTFPM)topology,focusing on its body design,electromagnetic characteristics and structural optimization research content,and at the same time designing and manufacturing one Experimental prototype to verify the simulation results.The main research content of the thesis includes the following parts:(Ⅰ)A U-shaped FCTFPM topology is proposed,the topology and working principle of the motor are elaborated,the mathematical model of FCTFPM is established to analyze the operation of the motor,and the power size calculation formula of FCTFPM is deduced according to the structural size parameters of the motor,and the motor model is determined the main size parameter value.(Ⅱ)In order to effectively shorten the design cycle of the motor and improve the accuracy of the model,consider the saturation of the iron core material,establish a three-dimensional nonlinear equivalent magnetic circuit model of the FCTFPM model,and use the nodal method to establish a nodal matrix of the nonlinear equivalent magnetic circuit model.Solve the nodal matrix to get the waveform diagram of flux linkage,no-load back EMF and torque.(Ⅲ)In order to obtain the advantages and disadvantages of the soft magnetic alloy 1J22,a finite element simulation model was established.Compare and analyze the magnetic field distribution,back EMF,cogging torque,cross-direction reactance,torque and efficiency of FCTFPM using soft magnetic alloy 1J22 and silicon steel sheet M330-50 A,and the parameter scanning method is used to determine the factors that affect the motor torque ripple and cogging torque in the motor’s structural size parameters.(Ⅳ)Use the VBScript script of Maxwell software combined with the proxy model to optimize the design method of FCTFPM,and determine the optimization objective function and optimization variables,and build an efficient global optimization algorithm(Efficient Global Optimization,EGO)based on the Kriging proxy model and EI plus point criteria.The structure size is optimized,and the optimized results show that the cogging torque and torque ripple of FCTFPM are significantly reduced,and the performance is significantly improved.(Ⅴ)In order to verify and analyze the finite element simulation results,a FCTFPM prototype is designed and manufactured.The experimental platform of the prototype is built.The electromagnetic characteristic parameters such as no-load back EMF and cogging torque of the prototype are measured.Compared with the finite element simulation results,the rationality of the motor design and the correctness of the finite element simulation results are verified and analyzed. |
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